Machine for perforating stones



June 1965 J. SCHLUCHTER 3,190,278

MACHINE FOR PERFORATING STONES Filed Feb. 19, 1963 2 Sheets-Sheet 1 FIG. 7

June 22, 1965 J. SCHLUCHTER 3,190,278

MACHINE FOR PERFORATING STONES Filed Feb. 19, 1963 2 Sheets-Sheet 2' FIG.3

United States Patent 0 9 Claims. for. 125-30 The present application is a continuation-in-part of my prior co-pending application Ser. No. 860,557 filed on December 18, 1959, now abandoned.

The object of my invention is an improved high-speed drilling machine for perforating, by means of a rotary drill, hard material such as metals, ceramic ware, stones for industrial purposes, stones for dies and stones for the watch-making industry.

According to my invention, the drill shaft is subjected to the action of means imparting thereto an axial vibratory movement of a reduced amplitude.

It is known that such an axial vibration can be achieved by ultrasonic excitation of a transducer. This is obtained by means of the excitation voltage through brush contacts being transmitted to the transducer fixed on the shaft. The resulting abrasion is a great disadvantage at high rotation speeds which are required for drilling hard materials.

Moreover, parts rotating at high speeds must be well balanced so as to ensure good dynamic equilibrium. However, additional stresses imparted to the rotating part, such as the pressures of the brush contacts, impair the dynamic equilibrium.

Another disadvantage of drills of this kind is the arrangement of the driving motor at the upper end of the shaft, which also prevents good dynamic equilibrium at high rotation speeds.

It is therefore an object of my invention to provide a drill with axial vibration which does not have a transducer on the shaft, which would have to be fed through sliding contacts.

Another object of my invention is to improve the dynamic equilibrium of the shaft by appropriate location of the driving motor in relation to the shaft.

Another object of my invention is to provide a drilling machine of very simple construction the maintenance of which is easy and including only a few parts which are practically not subject to abrasion.

Another object of my invention is to regulate the oscillation amplitude of the drill in an easy and accurate manner.

Another object of my invention is to provide a simple and accurate adjustment of the shaft.

Another object of my invention is to permit easy lubri cation of the shaft bearings.

The above advantages may be achieved by means of an improved high speed drilling machine energized from external power sources for perforating stones and similar hard materials, comprising a shaft having oppositely disposed ends and a longitudinal axis, the shaft being mounted for rotation about and reciprocation along said longitudinal axis; drilling means mounted in one of said oppositely disposed ends of said shaft; bearings supporting said shaft, mounted adjacent said oppositely disposed ends; motor means for rotating said shaft at high speeds, said motor means comprising a mechanically unconnected rotor portion and a stator portion, said motor means being energized from one of said power sources through its stator portion thereby eliminating frictional power connection with moving parts, the rotor portion being mounted on said shaft intermediate said bearings thereby insuring dynamic stability of shaft and rotor at said high ice speeds; an alternating current electro-magnet means, energized from another of said power sources, fixedly mounted opposite the other of said oppositely disposed ends of the shaft, said electro-magnet means being adapted to magnetically attract and repel said shaft when supplied with alternating current from the other of said power sources and thereby reciprocate said shaft along its longitudinal axis at twice the frequency of the supplied alternating current according to the changes produced by said alternating current in the polarity of the electro-magnet means, whereby said shaft is simultaneously rotated and reciprocated without frictional loss from connections with said power sources, said shaft being thereby rotated and reciprocated at increased speeds and efiiciency for given power supplies.

As an alternative to an electric driving motor, my invention further provides a motor means comprising a fluid motor having a blade wheel mounted on said shaft and a stationary nozzle mounted adjacent said blade wheel, said nozzle being adapted to project a jet of fluid to impinge on said blade wheel.

In the accompanying drawings illustrating, by way of example, various embodiments of my invention:

FIGS. 1, 2 and 3 are respectively side views, partially in section, of three different embodiments of my invention.

In the first embodiment illustrated in FIG. 1, the machine includes a frame shown only partly at 1, said frame carrying a headstock 2 in which bearings 3 rotatably carry a shaft 4 having at its lower end the chuck 5 carrying rigidly a drill 6.

The shaft is provided with an axial clearance defined by the two stops '7. The rotor S of an electric motor operating at a high frequency is mounted on the shaft 4, the stator of said motor being provided with a winding 10. The upper section of the headstock is provided with a recess inside of which is fitted an clectromagnet, the winding 11 of which is fed with A.C. and surrounds a core 12. The latter is provided with a conical recess 13 engaged by the conical tip 14 of the shaft 4.

During the drilling operation, the shaft is driven at a high speed and the drill carried by the shaft 4 engages the work to be machined (not illustrated), through the agency of abrading material which may be supplied in usual manner with a liquid coolant by a suitable nozzle (not shown).

The electromagnet acts on the tip 14 of the shaft so as to impart to the drill an axial vibratory movement, which vibratory movement allows a better distribution of the abrading material over the operative surface of the drill and over the surface of the bore which is being drilled. This leads to a considerable improvement of the quality and speed of operation.

It results therefrom that in the described embodiment according to FIGURE 1, the shaft 4 is in contact only with the two stationary bearings 3 and is symmetrically loaded owing to the arrangement of the rotor in the center between the two bearings. Moreover, the shaft is maintained in axial vibration by an electromagnet lying at the top of the shaft, no contact being, however, necessary between the conical tip 14 and the conical recess 13 of the magnet core 12.

The magnet is preferably fed with A.C. from a power source so as to magnetically attract and repel the shaft at twice the frequency of supplied A.C., thereby reciprocating said shaft.

In the second embodiment illustrated in FIG. 2, the shaft 21 is driven in rotation by a jet of fluid projected by a nozzle 22 and impinging on a blade wheel 23 rigid with the shaft. The upper end 24 of the shaft enters freely the central opening 25 extending coaxially through the electromagnet winding 26, said electromagnet providing, as in the case of the preceding embodiment, for the vibratory axial reciprocation of the shaft.

In the third embodiment illustrated in FIG. 3, the casing of the headstock 27 includes a central cylindrical section 28 associated with a housing 31 inside which is fitted an electromagnet, the winding 32 of which is fed with AC. and surrounds a core 33. Core 33 is provided alLits. upper end with a thread and is screwed into the cover '30 which permits easy adjustment of the amplitude of' the shaft vibration by turning the core. The latter is provided with a conical recess 34 adapted to be engaged by the tip 35 of the shaft 36. Said arrangement imparts, upon energization of the electromagnet, an axial movement to the shaft carrying at its end a drill 37. a 1

The shaft revolves inside two ball bearings 38' and 3 housed'each inside a reinforcement40 incorporated with an elastic diaphragm 41. The outer periphery of each diaphragm is clamped between themembers 28 and 29 or 28 and30 of .the. casing, as the case may be. -Said diaphragm being elastically deformable, in a direction parallel with the axis of the shaftand non-deformable in a radial direction, the shaft may readily vibrate axially, while remaining in perfect centered relationship with reference to the casing.

Furthermore, the central section 28 of the casing is slightly oversized with reference to the spacing between the two bearings, the two diaphragms are permanently held in a tensioned condition with reference to each other,

so that the spindle is urged, when inoperative, into a welldefined position.

The diaphragms are fitted l'eakproof both on the casing and on the bearings, sothat a stream of lubricating oil passing through the casing may be forced through said bearings.

.In the embodimentillustrated, the oil is injected through the pipe 42'and passes out of the latter into a second tube 43 and a bladed Wheel 44 fitted on the shaft controls the flow of saidoil through the machine.

In all'th'e embodiments illustrated, the frequency of thevibration may be accurately adjusted by means of a known frequency regulator for the current energizing the electromagnet, said regulator being inserted in the circuit feeding the latter.

What I claim is:

.1. An improved high speed drilling machine energized from external power sources forperforating stones and similar hard materials comprising: a casing, a shaft, having oppositely disposed ends and a longitudinal axis,;

mounted for rotation in said casing about, and reciproca tion along,.said longitudinal axis; drilling means mounted in one of'said oppositely: disposed ends of said shaft; bean ings. supporting said shaft, mounted adjacent said oppo sitely disposed ends; motor means for rotating said shaft at highspeeds, said motor. means comprising a mechanically unconnected rotor portion and a stator portion, said motor means being energized from one of saidpowfer sources through its stator portion thereby eliminating fric tional power connection with moving parts, the rotor portion being mounted on said shaft intermediate said bearings thereby insuring dynamic stability of the'shaft and v rotor at said high speeds; an alternating current 'electro- I magnet means, energized from another ,of said power sources, fixedly mounted opposite the other of said oppositely disposed .ends of the shaft, said 'electro-magnet means being adapted to magnetically attract and repel said shaft when supplied with alternating currentfrom the other of said power sources and to thereby reciprocate said shaft along its longitudinal axis at twice the frequency of supplied alternating current according to the changes produced by'said alternatingcurrent in the polarity of the electro-rnagnet means, whereby said shaft is simultaneously rotated and reciprocated without frictional loss from connections with saidpower source, said shaft being thereby rotated and reciprocated at increasedspeeds and efficiency for given power supplies.

2. A machine as described in claim 1 wherein said motor means comprises a fluidmotor having a..blade wheel mounted 'on said shaft .andja stationary :nozzle mounted adjacent said blade wheel, said nozzle being adapted to project a jet of fluidto impinge on saidblade wheel.

4. A machineas described in.claim.1,"wherein said electro-magnetmeans is providedwith' a core lying in the axis of said shaft and havinga conical recess at the end'facing the shaftQthe shaft having a conical tip designed to engagesaid conical recess.

2 5 5. A machine as described in claim 1, wherein the electro-magnet means is arranged insidean upper cover in the drilling machine casing and is provided with a core having. at its upper end a threaded portion screwed into said cover to permit axial'adjustment of saidcore.

3O 1 6. A machine as described in claim 1', in which said bearings rotatably supporting .said shaft are secured'to yieldable diaphragms which are fixed onto a support so that said bearings may reciprocate together with vsaid shaft and drilling means under the action of said electromagnet.

support onto which the yieldable diaphragms are secured is fixed onthe casing so that'said bearings may reciprocate together. .with said shaft and drilling means .under the action of said electro-magnet' :rneans' and provided with means to feed axlubricantsin'to said casing onone 4-5 side of said diaphragms and to extract it from the casing on the other side of sai'ddiaphrag'rns.

9. A machine as described in claim 8 in which said means to feed the lubricant comprise .a bladed wheel carried on said shaft.

References Cited by the Examiner UNITED STATES: PATENTS FOREIGN PATENTS 546,243 4/56 Belgium.

6 LESTER M. SWINGLE, Primary Examiner.

JOHN C. CHRISTIE, Examiner. 

1. AN IMPROVED HIGH SPEED DRILLING MACHINE ENERGIZED FROM EXTERNAL POWER SOURCES FOR PERFORATING STONES AND SIMILAR HARD MATERIAL COMPRISING: A CASING, A SHAFT HAVING OPPOSITELY DISPOSED ENDS AND A LONGITUDINAL AXIS, MOUNTED FOR ROTATION IN SAID CASING ABOUT, AND RECIPROCATION ALONG, SAID LONGITUDINAL AXIS; DRILLING MEANS MOUNTED IN ONE OF SAID OPPOSITELY DISPOSED ENDS OF SAID SHAFT; BEARINGS SUPPORTING SAID SHAFT, MOUNTED ADJACENT SAID OPPOSITELY DISPOSED ENDS; MOTOR MEANS FOR ROTATING SAID SHAFT AT HIGH SPEEDS, SAID MOTOR MEANS COMPRISING A MECHANICALLY UNCONNECTED ROTOR PORTION AND A STATOR PORTION, SAID MOTOR MEANS BEING ENERGIZED FROM ONE OF SAID POWER SOURCES THROUGH ITS STATOR PORTION THEREBY ELIMINATIONG FRICTIONAL POWER CONNECTION WITH MOVING PARTS, THE ROTOR PORTION BEING MOUNTED ON SAID SHAFT INTERMEDIATE SAID BEARINGS THEREBY INSURING DYNAMIC STABILITY OF THE SHAFT AND ROTOR AT SAID HIGH SPEEDS; AN ALTERNATING CURRENT ELECTROMAGNET MEANS, ENERGIZED FROM ANOTHER OF SAID POWER SOURCE, FIXEDLY MOUNTED OPPOSITE THE OTHER OF SAID OPPOSITELY DISPOSED ENDS OF THE SHAFT, SAID ELECTRO-MAGNET MEANS BEING ADAPTED TO MAGNETICALLY ATTRACT AND REPEL SAID SHAFT WHEN SUPPLIED WITH ALTERNATING CURRENT FROM THE OTHER OF SAID POWER SOURCES A TO THEREBY RECIPROCATE SAID SHAFT ALONG ITS LONGITUDINAL AXIS AT TWICE THE FREQUENCY OF SUPPLIED ALTERNATING CURRENT ACCORDING TO THE CHANGES PRODUCED BY SAID ALTERNATING CURRENT IN THE POLARITY OF THE ELECTRO-MAGNET MEANS, WHEREBY SAID SHAFT IS SIMULTANEOUSLY ROTATED AND RECIPROCATED WITHOUT FRICTIONAL LOSS CONNECTIONS WITH SAID POWER SOURCE, SAID SHAFT BEING THEREBY ROTATED AND RECIPROCATED AT INCREASED SPEEDS AND EFFICIENCY FOR GIVEN POWER SUPPLIES. 